低温氮化对1Cr11不锈钢耐双相流冲刷腐蚀性能的影响  

Effects of Low Temperature Nitriding Process on Errosion-Corrosion Resistance of 1Cr11 Stainless Steel

作　　者：潘东[1] 党理 杨屹[1] 王均[1] 

机构地区：[1]四川大学制造科学与工程学院,成都610065

出　　处：《中国表面工程》2015年第5期37-43,共7页China Surface Engineering

基　　金：国家自然科学基金(51471112)

摘　　要：为研究低温盐浴氮化提升马氏体钢耐冲刷腐蚀的机理,在410、430和450℃不同温度下对1Cr11不锈钢盐浴氮化8h。通过光学显微镜,X射线衍射分析仪(XRD),显微硬度仪对渗氮层的渗氮层厚度、显微组织及显微硬度进行研究,通过电化学工作站循环伏安法和双相流冲刷腐蚀模拟试验研究不锈钢耐蚀性。结果表明,渗氮层包括化合物层和扩散层,化合物层主要由N的过饱和固溶体αN和含氮化合物ε-Fe2-3N组成。渗氮层显微硬度约为基体硬度3倍;循环伏安法表明渗氮层和基体在NaCl溶液中均发生钝化,但渗氮层表面钝化膜在溶解后具有自我修复能力,抗点蚀能力好。经过120h的冲刷腐蚀模拟试验,氮化样品质量损失速率远低于未处理试样的质量损失速率,氮化可以有效提升试样的耐冲蚀性能。To study the mechanism of erosion corrosion resistance of martensitic stainless steel by low temperature bath nitriding. 1Cr11 stainless steel was nitrided in salt bath at 410, 430 and 450℃ for 8 h. The thickness, microstructure and microhardness of the nitrided case were detected through the optical microscope, XRD instrument and a micro-hard- ness tester. The corrosion resistance of stainless steel was tested through electrochemical workstation cyclic voltammetry （CV） and multiphase flow erosion corrosion simulation test. The results show that the nitrided case consists of a com- pound layer and a diffusion layer. The compound layer consists mainly of the solid solution of nitrogen （αN） and nitrogen compound （ε-Fe2-3N）. The microhardness of the nitrided case is about 3 times harder than that of the substrate. CV shows that the nitrided case and the substrate passivate in NaCl solution, however after dissolution, self-repairing ability and stronger pitting resistance are found in the passive film transformed from nitrided case. After erosion corrosion simu- lation test for 120 h, the nitrided sample mass loss rate is far slow than that of the untreated one, showing that the ero- sion corrosion resistance of 1Cr11 can be significantly improved by low temperature bath nitriding.

关 键 词：不锈钢 盐浴氮化 冲刷腐蚀 循环伏安法 

分 类 号：TG174.44[金属学及工艺—金属表面处理]